A stocky, blunt-faced damselfish holding a patch of shallow rock and rarely straying more than a meter from it.
A territory in this genus is an asset with a value. It contains a food supply the fish maintains, a hole to sleep in, and a cleaned patch of rock where eggs will be laid, and the size and quality of that patch decides whether a male gets to breed at all. Fish fight over them, inherit them, and are evicted from them; a good territory changes hands rather than disappearing.
The eggs are laid on the cleaned rock and guarded by the male, who fans them, picks out dead ones and attacks anything that comes near for the several days it takes them to hatch. That is the other half of what the territory is for.
Juveniles look nothing like the adults - a bright blue line along the back and a dark eyespot on the fin - and hold their own small territories from the day they settle. Thirteen centimeters (5 in) of fish that spends its life on a few square meters.
The species. Stegastes punctatus (Quoy & Gaimard 1825) - spotted. ETYFish
- stocky dark brown fish with a blunt rounded snout
- juveniles with a bright blue line along the back and a dark spot on the dorsal fin
- hovers over one patch of rock and returns to it constantly
- length up to 13 cm
Why it's threatened
There are no known major threats.
Threat classification from the IUCN Red List.
